Apparatus for working metals and other materials



May 14, 1968 G. MARTELLE 3,382,696

APPARATUS FOR WORKING METALS AND OTHER MATERIALS Filed Sept. '7, 1965rryc United States Patent O 3,382,696 APPARATUS FOR WORKING METALS ANDOTHER MATERHALS Ghislain Martelee, 71 Quai de Rome, Liege, Belgium FiledSept. 7, 1965, Ser. No. 485,514 Claims priority, application Luxembourg,Sept. 8, 1964,

s claims. (ci. 'l2- tarn ABSTRACT F THE DlSSL-GSURE This inventionrelates to improvements in and relating to working metals and othermaterials. This expression is to be understood to mean all suchoperations as rolling, hammering, forging, drawing, spinning,wiredrawing, and the like and in general any operation which causes a`deep or superficial change in shape in the material Ibeing worked.

It is applicable to all materials, whether metallic or not, which arecapable of being worked by any of the above operations. lt is howevermore specially adapted to .the production of fiat metallic products.

The invention referred to above has as its object the modification ofthe cross-section and possibly the form of a basic material, theimparting to the material a given surface, for example a smooth surface,and also certain mechanical properties. Some special aspects proper tocertain of these processes are briefly recalled below.

In the commonest rolling process, these modifications are obtained bypassing a basic material (in the form of slabs, blooms, ingots, in thecase of steel) through a nip between motor driven rolls, the axes ofwhich are fixed during any particular pass.

At each pass the resultant of a part of the compressive forces exertedby the rolls on the material being rolled, and on the other hand tensionfrom the tractive force exerted in the direction of movement of the saidmaterial, produce in it a permanent deformation. This permanentdeformation may only exist at the surface, as usually happens inskin-pass operations or any other operations of a superficial or surfacenature.

It is known that to assist in rendering the rolling operationtechnically efficient and commercially' viable, it is advantageous toreduce the diameter of the rolls and support them on others of largerdiameter. It is thus possible to reduce the deformations due to theflexing of the working rolls and to reduce the tolerances of the rolledproducts.

It has also been proposed to design a planetary type mill, that is tosay a mill comprising a set of small working rolls distributed round thecircumference of two large motor driven cylinders, which because oftheir rotation, successively bring all the small working rolls intocontact with the material to be rolled in accordance with a processresembling that known as down-stream milling. This mill is however4noisy in operation and is subjected to repeated shocks.

ln the conventional process of drawing or wiredrawing, the material tobe drawn or wiredrawn is forcibly pulled through a die, the walls ofwhich exert great pressures on the material and produce the desiredcross-section. In

ICC

this type of operation considerable friction and heat are produced,jammings are common and the die wears rapidly in spite of adequatelubrication.

In the case of the spinning process, the drawbacks remain of the samekind, although reduced by the use of certain special lubricants such asviscous glass. For these two processes it should be pointed out that theenergy is solely supplied to the material either by traction or bycompression, which however imposes a restriction on the forcetransmitted to the said material as otherwise there would be analteration in its mechanical properties.

This invention relates to apparatus which avoids or substantiallyreduces the draw-backs mentioned above.

The working of material according to the present invention isessentially characterized in that the basic material is reduced 'betweenplural rolls or dies, of suitable profile, each pair being made tofollow convergent and/ or parallel paths in such a way that they blockthe material progressively and in such a way that the profile along theenvelope Surface, produced by the gcneratrices of Contact between rollsor dies and the material during the working along the line of movementof the said rolls or dies, is oblique to the axis of the material duringthe treatment, the said Obliquity being either linear or curved with avariable radius, the said material being further possibly subjected t0 atractive force or a thrust independent of the rolls or dies.

The above mode of operation offers the important advantage ofsubstantially reducing the shocks transmitted to the frame and ensuringa finished product manufactured to the closest tolerances.

According to another advantageous feature, the rolls have the samediameter or have an increasing diameter according to Whether or not theyare placed within convergent or parallel guides or slides. lt should benoted that it ispossible to use the process in the invention impartingto the rolls a movement in the reverse direction from that of theextraction of the -treated material.

in accordance with yet another advantageous feature the rolls areprovided with pedestal bearings in which they rotate idly so that eachroll can rotate at its own speed, which may be different from that ofthe other rolls.

According to a further feature of the method in accordance with theinvention, the rolling operation is completed by means of several pairsof rolls, the spacing between the two rolls of every pair being thesa-me, which allows products to be obtained with especially closetolerances.

in the case where convergent guides are used it has been foundadvantageous to make the guides precede and follow inlet and dischargeconnecting elements making possible on the one hand the progressivegripping of the material by the inlet rolls and on the other hand theprogressive release of this material by the discharge roll, whichsubstantially avoids shock and corresponding noise, and on the otherhand obtains a gradual placing under load and release from load of theframe.

It has likewise been found advantageous lto subject temporarlly all orpart of the tables of the rolls to a fixed supporting action, whichreduces the deformation of the rolls and allows the product to beimpelled better due to the tangential force developed between thesupport and the tables of the rolls.

In accordance with other advantageous embodiment, the rolls are usedcontinuously and preferably in a closed circuit, that is lto say eachroll after having carried out its rolling operation, is reintroduced atthe input side of the device as if it were a new roll. The advantage ofsuch a mode of embodiment is selfcvident.

A preferred embodiment of the device forming the subject matter of thepresent invention is characterized in that comprises: a frame having twoflanges facing one another and each provided with two slides or rollerbearn ings, which may be convergent and/ or parallel, the slides of onefrange being similar to those of the other similarly arranged facingthese latter.

Two sets of rolls provided at each end with a journal, each roll restingon the two anges by means of these journals and correspondin g bearingblocks, accommodated in the said slides or bearings, the axis of therolls being perpendicular to the plane of the flanges.

A device causing the rolls t0 move all together at the same time in theslides or bearings.

A device maintaining the distance between the rolls of a given set.

vlt must be expressly understood that in the above device the rolls maybe replaced by any kind of dies or any other treatment member.

According to a feature, the feed device for the rolls is of the endlesschain type.

According to another feat-ure, the convergent bearings or slides areprovided at each of their ends with an extension parallel to the planebisecting their angle of convergence, and preferably their connectiongradually.

According to yet another feature these parallel extensions are movableand adjustable.

it has also been found advantageous in some cases to provide the deviceof the invention with a member pulling or thrusting the product treatedand/ or the basic material.

Specific embodiments of the invention will now be described by way ofexample with reference to the accompanying drawing, in which:

FIGURE l shows a longitudinal section through a rolling mill forcarrying out the method in accordance with the invention,

FlGURE 2 is a cross-section taken on the line li-II oi FIGURE 1.

Referring to the drawing, a rolling mill comprises a cage formed by apair of rivid uprights 1 (only one of which is shown) spaced apart bycross-members 2. Channel-like guides 3 formed in the inner face of eachupright 1 provide paths 5 along which are arranged to travel bearingblocks i formed as roller bearings, the outer races of which roll in theguides 3. Each bearing block fi co-operates with a bearing blockassociated with the lupright opposite and following a similar path toidly support a roll o. Adjacent bearing blocks are spaced and connectedby links 7 to form two endless chains of rolls which, because of theorientation of the paths 5, are caused to converge towards the dischargeend of the mill.

Each endless chain is provided with two sets of sprockets 8 which serveto drive it and maintain its rolls in phase with those in the otherchain. Motion is transmitted from the sprockets to the chains by teeth 9which engage the journals lil of the rolls 6.

A strip 11 of the material to be rolled enters the mill where the chainsof rolls have the greatest spacing and leaves at the other end where thechains of rolls have the smallest spacing. It is then driven by aconveying means not shown in the drawing.

The mill further comprises at the inlet and outlet, moveable guidecomponents 12 which act as a progressive connecting element to the fixedconvergent guides.

guide components 12 may 4move parallel to the convergent guides and havea surface parallel to the materials axis which makes it possible forthem to admit materials of different thicknesses at the inlet side andto modify the thickness of the rolled product.

The guides 12 consist of a series of fiat members 13 slidable againstthe flat surface of the uprights l.

The members 13 have flanges to prevent the components 12 escaping ifthere is no material being rolled.

T he components can slide, supported on surfaces which are parallel tothe guides of the uprights.

The other faces i5 of these components are parallel to one another.

By moving the components 12 at the inlet along the CII surface 14 awayfrom the mill, material having greater thicknesses may be admitted,while the final thickness of the rolled material may be increased bymoving the components at the outlet towards the mill, or reduced bymoving them away from it.

The control devices for the slides 12 are not shown in the figure. Theymay be for-med for example by hydraulic jacks which require acomparatively large travel if the gradient of the guides is small andvice versa.

The rolling forces both at the input side and at the discharge sidedecrease towards the end of the mill, which makes it possible to providea form with a section which decreases (with equal strength) towards theends.

The mill described above is operated as follows:

The inlet slide components 12 are moved by a hydraulic jack to aposition wherein the distance between the two pairs of rolls occupyingthe leading positions is greater than the thickness of the material tobe rolled, which allows the material to be easily introduced.

The discharge slide components 12 are moved by means of a hydraulic jackto obtain a distance between the three rolls occupying the trailingposition which is equal to the desired thickness ofthe product.

The material to be treated is then inserted in the device and thesprockets are set in motion at low speed. At this moment the ixedsupport may be brought into place so as to produce the entrainment oflthe material because of the forces described above.

The material then travels progressively between the different pairs ofrolls; the rate of flow of the material being constant and the reductionprogressive, the flow speed gradually increases as does also the speedof rotation of the rolls which easily adapt themselves to thiscontinuous increase in speed as they are mounted idly in their bearingblocks.

The inlet slide components 12 are then moved to obtain a distancebetween the instantaneous two pairs of leading rolls equal to thethickness of the product at the inlet. This avoids an abrupt attack onthe material and the rolling commences gradually, noiselessly andwithout exaggerated shock.

The strip 11 at the outlet is then fixed to the conveying means and thesprockets are speeded-up until the optimum speed is reached.

Automatic control of the discharge thickness can be obtained by actingon the hydraulic jack controlling the movement of the slides 12.

Apart from those already mentioned the method and apparatus of theinvention offer the following further advantages-due to the wedgingeffect of the convergent guides, the rolling forces are to a largeextent taken up by the frame, the screws or control chains or thesupport screws only taking a very small part of these forces, bycontrast with present conventional practice where the screws actuatedduring the passage of the product take up all the rolling operationforces.

This type of embodiment makes it possible to obtain products with veryclose tolerances of thickness; in fact, in the caseof a rollingoperation, the rolls acting in the parallel guides only roll the excessthicknesses arising from the yielding at the proceeding rolls.

The last pass is carried out practically without reduction, consequentlypractically without any force between the rolls and iinally practicallywithout yielding, that is to say at a thickness which is strictly equalto that desired.

This embodiment likewise makes possible (as has already been pointed outabove) a gradual attack of the material at the input side thus avoidingnoise and repeated shocks on the rolls and on the mechanical equipmentfor control purposes and for taking up the forces exerted.

lt is also important to note that the use of idler rolls nakes itpossible to avoid making windows in the upright cage, which windows inconventional rolling mills are necessary for the replacement of therolls, for passing through extension shafts, etc. The transmission offorces can thus be effected under favourable conditions.

It is advantageously possible to control the movement of the supportrolls of conventional rolling mills by means of hydraulic jacksactuating wedges with very sharply inclined surfaces.

The preceding description has described the case where the approachmovement of the rolls or dies is produced by means of guides or slides.The scope of the invention of course covers any other manner ofdesigning and producing a similar movement of the said rolls or diessuch as for instance any articulated system with extending arms, etc.

What I claim is:

1. A rolling mill comprising in combination a pair of opposed endlessroller chains having rolls journalled thereon, journals on the outersides of the chains, a pair of spaced uprights having confrontingsurfaces, cro-ssmembers securing together said uprights to form a cage,said confronting surfaces of said uprights having channellike paths inwhich said journals are disposed, drive means for circulating saidendless chains, guides for said chains located at the inlet and at theoutlet of the path between the chains for the material to be rolled, andmeans mounting said guides for sliding movement on and relative to saiduprights thereby to vary the distance between the rolls at said inletand at said outlet.

2. A rolling mill as claimed in claim 1, said paths converging from saidinlet towards said outlet.

3. A rolling mill as claimed in claim 1, said guides having guidesurfaces for the chains disposed parallel to the longitudinal axis ofthe product to be rolled.

4. A r-olling mill as claimed in claim 1, said drive means comprisingtoothed sprockets whose teeth engage between said journals.

5. A rolling mill as claimed in claim 1, and means mounting said guidesfor sliding movement on and relative to said uprights in a direction atan angle to the longitudinal axis of the material to be rolled, saidguides having guide surfaces for the chains parallel to the longitudinalaxis of the material to be rolled so that sliding movement of saidguides along said uprights moves said guide surfaces toward or away fromsaid axis.

References Cited UNITED STATES PATENTS 2,978,933 4/l96l Sendzimir 72-1902,811,060 10/ 1957 Sendzimir 72--190 2,792,730 5/1957 Cozzo 72-2412,684,000 7/1954 Holtz 72-190 FOREIGN PATENTS 908,849 4/ 1954 Germany.

CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner.

